Re: [RFC/RFA] find_pc_sect_psymtab(): symbol table not always complete

Joel Brobecker
2003-11-20T00:24:02Z

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> > 2003-11-19 J. Brobecker <brobecker@gnat.com>
> >
> > * symtab.c (find_pc_sect_psymtab): Refine the search for the
> > partial symtab corresponding to the given PC address, taking
> > into account the fact that the symbol table might be incomplete.
>
> FWIW, this looks good to me, but I'd like another comment on the new
> test to the effect of, the find_pc_sect_psymtab call will always return
> the closest symbol below pc in tpst. Threw me for a moment how you
> were just checking for the highest valued symbol.

Thanks for your feedback Daniel. I agree on that a comment is useful.
Here is a revised version of the patch. Is it better?

--
Joel

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Index: symtab.c
===================================================================
RCS file: /cvs/src/src/gdb/symtab.c,v
retrieving revision 1.122
diff -u -p -r1.122 symtab.c
--- symtab.c 8 Nov 2003 00:13:03 -0000 1.122
+++ symtab.c 20 Nov 2003 00:21:30 -0000
@@ -698,6 +698,8 @@ find_pc_sect_psymtab (CORE_ADDR pc, asec
if (pc >= pst->textlow && pc < pst->texthigh)
{
struct partial_symtab *tpst;
+ struct partial_symtab *best_pst = pst;
+ struct partial_symbol *best_psym = NULL;

/* An objfile that has its functions reordered might have
many partial symbol tables containing the PC, but
@@ -710,6 +712,11 @@ find_pc_sect_psymtab (CORE_ADDR pc, asec
if (msymbol == NULL)
return (pst);

+ /* The code range of partial symtabs sometimes overlap, so
+ we need to check all partial symtabs and find the one that
+ fits better for the given PC address. We select the partial
+ symtab that contains a symbol which address is closest to
+ the PC address. */
for (tpst = pst; tpst != NULL; tpst = tpst->next)
{
if (pc >= tpst->textlow && pc < tpst->texthigh)
@@ -721,9 +728,24 @@ find_pc_sect_psymtab (CORE_ADDR pc, asec
&& SYMBOL_VALUE_ADDRESS (p)
== SYMBOL_VALUE_ADDRESS (msymbol))
return (tpst);
+ if (p != NULL)
+ {
+ /* We found a symbol in this partial symtab which
+ matches PC, check whether it is closer than our
+ current BEST_PSYM. Since this symbol address is
+ necessarily lower or equal to PC, the symbol closer
+ to PC is the symbol which address is the highest. */
+ if (best_psym == NULL
+ || SYMBOL_VALUE_ADDRESS (p)
+ > SYMBOL_VALUE_ADDRESS (best_psym))
+ {
+ best_psym = p;
+ best_pst = tpst;
+ }
+ }
}
}
- return (pst);
+ return best_pst;
}
}
return (NULL);